Publications

Management of tundra swans (Cygnus columbianus) is hampered by a lack of information on their nesting and brood-rearing ecology. We studied tundra swan nesting and brood-rearing ecology on the Arctic National Wildlife Refuge (ANWR), Alaska, 1988-90. Nest success was 58% (n = 31) in 1988, 83% (n = 36) in 1989, 84% (n = 43) in 1990, and 76% (n = 110) for the 3 years. Nests were located...

We studied Black-legged Kittiwakes (Rissa tridactyla) in an Alaskan colony where movement of young among nests was possible because of moderate terrain and close nest spacing. Thirty-three percent of chicks in a focal group departed their nests prior to fledging, and seven of the vagrant chicks (58%) were adopted by foster parents. The overall frequency of adoption in three years was 8%...

The dynamics of mitochondrial and multilocus nuclear genotypic frequencies were monitored for 2 yr in experimental populations established with equal numbers of two poeciliid fishes (Gambusia affinis and Gambusia holbrooki) that hybridize naturally in the southeastern United States. In replicated "small-pool" populations (experiment I), 1018 sampled individuals at six time periods...

Experimental laboratory crosses and population experiments reveal significant differences in individual life-history traits and population demography between two related species of mosquitofish, Gambusia affinis and G. holbrooki. With respect to life-history traits, progeny from G. holbrooki exhibit larger size at birth and earlier age at sexual maturity than do progeny from G. affinis...

Decoy traps and rocket-nets were compared for capturing Northern Pintails (Anas acuta: hereafter pintails) during May 1991 on the Yukon Flats, Alaska. Males were captured at similar rates using both methods (1.38 vs. 1.07 males/trap d, respectively), but baited rocket-nets were more efficient than decoy traps for capturing females (0.52 vs. 0.12 females/trap d). There were no significant

We compared trends in breeding population size among cormorants, gulls, alcids, and others, among the Farallon Islands, and sites in northern California and Washington, Gulf of Alaska, and Bering Sea, but in most cases only during the last two decades. For a given species, trends were usually concordant within the same oceanographic domain, except for Rhinoceros Auklet, which increased...

I quantified ovarian rapid follicle growth (RFG) and regression of postovulatory follicles of Northern Pintails (Anas acuta), American Wigeon (A. americana), and Lesser Scaup (Aythya affinis) by a method that accounted for within-day variation in follicle size. Objective methods for identifying onset of RFG also are presented; this is crucial for accurate classification of breeding...

Leadership in ecological research on north-temperate-zone seabirds has long been associated with the region of the northeastern Atlantic, which enjoys a tradition of detailed, innovative work spanning several decades. Although the temperate North Pacific is home to several of the same species that figure prominently in the Atlantic and also has a host of interesting species found nowhere...

I studied feeding activity of Emperor Geese (Chen canagica) on the Alaska Peninsula during autumn migration, 1991. Scan samples were used to estimate the proportion of birds feeding in flocks as a measure of feeding intensity. Most geese fed during low tides and roosted during high tides. However, flocks with disproportionately more juveniles continued to feed during high tides in either...

The number of spectacled eiders nesting on two study areas near the Kashunuk River, on the central Yukon-Kuskokwim (Y-K) Delta, Alaska, declined by over 75% in the last 20 years. Nesting densities have remained low, but have not significantly declined since 1985. There has been no decrease in the reproductive effort of individual females as indicated by average clutch sizes. There has...

Only anecdotal information is available to assess whether populations of the 47 shorebird species that breed or winter west of the Rocky Mountains changed in size or distribution during the past century. Unregulated hunting from 1870 to 1927 reduced populations of several species, at least temporarily, and was a factor in bringing the Eskimo Curlew (Numenius borealis) close to extinction...

The Exxron Valdez oil spill (EVOS) on 24 March 1989 threatened extensive areas of prime sea otter (Enhydra lutris) habitat along the coasts of south-central Alaska. The spill occurred in northeastern Prince William Sound (PWS), and oil moved rapidly south and west through PWS into the Gulf of Alaska. Much of the coastline of western PWS was heavily oiled, and the slick eventually spread...